Definition by Jim

Paricipation was originally proposed in the context of agent. I'll suggest a broadening of that to address mutability and to allow agents to be defined as things/resources with an agency relationship to a process execution.

Participation of a thing/resource X in a process execution P implies a) that P would not have occurred as it did in the absence of X, and b) that according to the definition of X (in some out-of-scope ontology), P (processes of the type of which P is one execution) would be considered to be a normal part of its lifecycle (i.e. that such processes do not generate/destroy X nor change it to the extent it would be inconsistent with its definition).

The participation of X in P may imply that P would not have occurred at all without X, or that P's duration, products, or other attributes may have been different without X.

The effects of P on the state of X are implicit and undocumented by a participation relationship itself. Participation may be used when the effect of X on P is of interest (an oven participates in a cake baking process and we're concerned about the effect of the particular oven on baking and the quality of the cake) or when the effect of P on X are important (I may not want to buy a car that has participated in a crash).

The concept of control/agency is a subtype of participation which implies some form of signalling from X to P and possibly monitoring of P by X. (Control/agency also implies that the primary interest is the effect of X on P and not of P on X.)

If the changes to X, or the specific actions of X are of interest, they can be documented by a) defining resources/things that are more stateful versions of X (have an IVPT relation to X) that are used and generated by P (a car participates in a crash and we can define a 'crashed-car' object that describes the extent of the damage) , or b) defining intermediate control process executions that trigger P (e.g. a person participatesin a 'buttonPress' process execution that triggers a 'createWidget' process execution).